Self-venting spout for bag filling machines



Nov. 23, 1965 E. M. LAU

SELF-VENTING SPOUT FOR BAG FILLING MACHINES Filed Feb. 28, 1965 2Sheets-Sheet 1 w/l/l/l/ M S FIEE] NOV. 23, 1965 LAU 3,219,072

SELF-VENTING SPOUT FOR BAG FILLING MACHINES Filed Feb. 28, 1963 2Sheets-Sheet 2 yz z dzw United States Patent 3,219,072 SELF-VENTINGSPOUT FOR BAG FILLING MACHINES Erwin M. Lau, Dolton, Ill., assignor toBlack Products Co., Chicago, 11]., a corporation of Illinois Filed Feb.28, 1963, Ser. No. 261,898 6 Claims. (Cl. 141286) The presentapplication is a continuation-in-part of my earlier application SerialNo. 244,818, filed December 14, 1962, now abandoned, and the subjectmatter thereof is hereby incorporated by reference into thisapplication, insofar as consistent with the present disclosure.

This invention relates to a filter type self venting spout for a bagfilling machine, and has for its general object the provision of aconstruction which materially improves the overall efliciency of theventing arrangement and the bag filling operation.

During the operation of a bag filling machine, it is desirable toprevent the building up of a back pressure within the bag. This isparticularly true in the case of a fluidizing type of machine.

However, the use of a filter in the venting means tends to slow up thefilling operation very materially when operating with fine powders. Thisis for the reason that the efliciency of the venting arrangement isdecreased both by the clogging or partial clogging of the filter andalso bythe excessive use of blowout means for cleaning the same, thereason for the latter being that during the blowout period, venting doesnot take place.

The present invention is an improvement over the invention of my priorapplication, Serial No. 118,165, filed June 19, 1961, now Patent No.3,102,562, granted September 3, 1963, in which the filter was disposedtransversely of the vent passageway provided by the spout structure. Ina commercial embodiment of said prior application the transverselydisposed filter was of annular shape and had an area of approximatelyfour square inches. In the case of certain fine powders, it wasnecessary to provide a two second blowout period after every fourseconds of venting, thus reducing the overall efiiciency by one third.

According to the present invention I am enabled to provide a filterhaving several times the area, with the result that under similarconditions, only a single two to four second blowout period is requiredfor an entire bag filling operation of from twenty to forty seconds induration.

It is an object of the present invention to provide a self venting spoutwhich includes a comparatively large area filter so that the filter doesnot have to be blown out as frequently in order to avoid clogging. v

A further .object is to provide a self venting spout in which theefiiciency of the air removing arrangement is enhanced by the use ofsuction.

Still another object is to provide a self venting spout having animproved filter cleaning arrangement.

Other objects, features and advantages will become apparent as thedescription proceeds.

With reference now to the drawings in which like reference numeralsrepresent like parts:

FIG. 1 is a sectional elevation showing a preferred embodiment of myinvention as applied to a bag filling machine of the fluidizing type;

FIG. 2 is an enlarged vertical sectional elevation of the spout;

FIG. 3 is an elevation of the internal structure when removed from thespout;

FIG. 4 is a section taken along line 44 of FIG. 3;

FIG. 5 is a section taken along line 6-6 of FIG. 1 showing the aspiratorof FIG. 1;

FIG. 6 is a plan section taken along line 66 of FIG. 5 showing the pinchvalve on the vent tube; and

FIG. 7 is a diagram showing a modification of the blowout means.

With reference now to FIG. 1, the bag filling machine includes a spout10 which is adapted to project through the opening of a valve bag 11.The spout 10 is mounted on a floating frame 12 which is supported in asupport structure 13 by means of spacer points 14. The arrangement issuch as to permit limited vertical movement of the floating frame withrespect to the support structure 13 so that when a predetermined amountof material has been fed into the bag, the weight of the bag and itscontents will actuate a scale mechanism 20 to terminate the bag fillingoperation. The floating frame is connected to the scale mechanism 20.

The bag filling machine includes a framework 15 on which the supportstructure 13 is mounted, and which framework also supports a chamber 16which receives the material that is fed into the bag 11. A flexible tube17, of rubber or the like, extends between the chamber 16 and the spout10 so that the material within the chamber 16 can pass through the spoutand into the bag. The flexibility of the tube 17 permits the up and downmotion of the spout 10 and the floating frame 12 which is incident tothe operation of the scale mechanism 20.

The flexible tube is engaged by an air actuated pinch valve 18 whichserves to cut off the flow of material through the spout. The chamber 16includes a diffuser pad 19 located near the outlet for fluidizing thematerial contained within the chamber 16 so that it will be caused toflow through the spout into the bag.

As shown in FIGS. 1 and 2, the spout includes an outer shell 21 having asupport collar 22 by means of which it may be suitably mounted on thefloating frame 12. The support collar 22 has integrally formed therewitha tapering shank portion 23 which forms a tight fit with theopening ofthe bag 11.

Disposedwithin the shell 21 is an internal structure 24 shown in FIGS. 2and 3 which divides the interior of the shell 21 longitudinally into twoparts, one part being a vent chamber 25, and the other being a materialflow passageway 26 which communicates with the chamber 16. Communicationbetween the portions 25 and 26 is provided by a porous wall or filterelement 29 so that the fluidizing air may be removed from the materialas it is passing through the spout. 'I he porous Wall serves as afilter, and suitable blowout means are provided so that dust or fineparticles entrapped thereby can be returned to the stream of materialflow.

The porous wallmay be of any suitable filter material, such as sinteredmetal, wire screening, or asleeve 29 of dust collector fabric as shown,the latter being preferred. As shown in FIG. 2, the internal structure24 comprises an inner tubular member 27 having an opening 28 formed inits upper half and extending for substantially its full length. Thefabric sleeve 29 surrounds the tube 27 and is secured thereto by clamps30. A front ring 31 and rubber O-ring gasket 32, mounted on the. frontend of the tube 27, seal off the front end of the vent chamber 25. Thetube 27 is mounted within the shell by a collar 33 which engages therear end of the support collar 22. The collar 33 has an opening 34therein and a fitting 35 is secured thereto which communicates with theatmosphere, either directly or by means of a flexible vent tube 36.

Suitable means may be provided to blow out the tubular .filter element29 at intervals to avoid clogging of the In operation, as the powderedor granular material is fluidized by the diffuser pad 19, it flowshorizontally out of the chamber 16, through the flexible tube 17 andpassageway 26 and into the bag 11. The fluidized material gives up itsfluidizing air as it passes under the exposed portion of the filterelement 29 in view of the pressure conditions present. As a result, thefluidizing air passes through the filter element 29 and thence is ventedto the atmosphere, but the powdered or granular material retainssufficient fluidity so that it will continue in its horizontal movementand drop into the bag 11.

The action may be enhanced by reducing the pressure in the vent chamber25 by suitable means, such as the aspirator arrangement 41 shown in FIG.5.

According to this aspect of my invention, the fitting 35 is in the formof an elbow, and an air supply tube 42 extends through the wall of theelbow, its outer end being concentrically located with respect to theouter end of the fitting and constituting a jet tube 42a. Thus a vacuumis produced in the vent chamber 25 which increases the pressuredifferential across the filter element 29 to increase the rate of airremoval.

The aspirator 41 also provides an effective blowout means. As shown inFIGS. 5 and 6, a pinch valve 43 engages the flexible tube 36 to cut offthe venting action. When this occurs, the air passing through the airsupply tube 42 will build up a pressure within the vent chamber 25,causing the reverse flow of air through the pores of the fabric of thefilter element 29, thus cleaning the same.

It has been found that this arrangement provides a very effective meansof cleaning the horizontally disposed filter for the reason that thepassage of air through the fabric in the reverse direction dislodges thedust by a fluidizing action at a time when it can be picked up by otherfluidized material which is flowing horizontally from the chamber 16into the bag.

The reverse flow of air through the filter preferably takes place duringthe first several seconds of the bag filling operation, because thefluidizing air, if not removed, can be used to expand the emptycollapsed bag. The duration of the blowout is controlled by a suitabletime delay switch.

In the FIG. 3 embodiment shown, the opening 28 is seven inches long, andthe tube 27 is :two inches in diameter. This provides a filter area ofabout twenty-two square inches. This can be compared with the foursquare inch area of the previously mentioned arrangement.

It will be seen therefore that according to the arrangement of FIGS. 2and 3, I am enabled to provide a filter having about five times thefilter area of the earlier arrangement in which the area of the filteris limited by the diameter of the spout.

Furthermore, the pressure conditions in a fluidizing machine are suchthat the efficiency of the air removal or venting action can be doubledby the aspirator arrangement shown.

At the conclusion of the bag filling operation, the bag is left on thespout for a second or two after the flow of material through the spouthas been cut off by the operation of the scale mechanism. Thus, thevacuum serves to evacuate the bag so that a more compact package isprovided.

The present invention profides a very efficient means of removing acomparatively large volume of air from the material as it is passingthrough the spout, and for filtering the same without interrupting theventing action during the period subsequent to the initial expansion ofthe collapsed bag.

The inner tube construction of FIGS. 2 and 3 is preferred because thelower portion of the wall of the material flow passageway 26 isnon-porous, thus avoiding a situation in which the wall friction isincreased due to adherence of fine particles to the filter element 29along the bottom of the passageway 26.

In FIG. 1, the spout is shown as being mounted on a scaling mechanismsuch as that shown in my Patent No. 2,936,994, but it is understood thatthe same is equally suitable for use in connection with other scalingmechanisms.

Although only preferred embodiments of my invention have been shown anddescribed herein, it will be understood that various modifications andchanges may be made in the constructions shown without departing fromthe spirit of my invention as pointed out in the appended claims.

I claim:

1. A self venting spout for a bag filling machine comprising an outershell adapted for cooperation with a bag to be filled, means providing avent chamber located within said shell, said vent chamber providingmeans including a filter element extending longitudinally of said shell,conduit means providing communication between said vent chamber and theatmosphere, a jet tube located in said conduit means to reduce thepressure within said vent chamber below atmospheric pressure, and airsupply means communicating with said jet tube.

2. A self venting spout as claimed in claim 1 which includes valve meanslocated in said conduit means at a point between said jet tube and theoutlet end of said conduit means whereby operation of said valve meanswill cause air to be supplied under pressure to said vent chamber.

3. A self venting spout as claimed in claim 1 including suction meanscommunicating with said vent outlet.

References Cited by the Examiner UNITED STATES PATENTS 1,437,876 12/1922Tyler 14l-9l XR 2,032,140 2/1936 Mallory et a1. 210232 XR 2,142,9901/1939 Belcher 14 1-286 XR 2,564,969 8/ 1951 Goldberg.

2,770,439 11/1956 Stafford et al 141-68 XR 2,936,994 5/1960 Lau 141-90XR LAVERNE D. GEIGER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,219,072 November 23, 1965 Erwin M. Lau

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 4, lines 45 and 46, strike out "3. A self venting spout asclaimed in claim 1 including suction means communicating with said ventoutlet."; in the heading to the printed specification, line 7, for "6Claims" read 2 Claims Signed and sealed this 6th day of September 1966.

SEAL) RNEST W. SWIDER EDWARD J. BRENNER nesting Officer Commissioner ofPatents

1. A SELF VENTING SPOUT FOR A BAG FILLING MACHINE COMPRISING AN OUTER SHELL ADAPTED FOR COOPERATION WITH A BAG TO BE FILLED, MEANS PROVIDING A VENT CHAMBER LOCATED WITHIN SAID SHELL, SAID VENT CHAMBER PROVIDING MEANS INCLUDING A FILTER ELEMENT EXTENDING LONGITUDINALLY OF SAID SHELL, CONDUIT MEANS PROVIDING COMMUNICATION BETWEEN SAID VENT CHAMBER AND THE ATMOSPHERE, A JET TUBE LOCATED IN SAID CONDUIT MEANS TO REDUCE THE PRESSURE WITHIN SAID VENT CHAMBER BELOW ATMOSPHERIC PRESSURE, SAID AIR SUPPLY MEANS COMMUNICATING WITH SAID JET TUBE. 